Just to follow up on Bob¡¯s message here...
On Aug 26, 2019, at 12:52 PM, Bob Jacobsen <rgj1927@...> wrote:
CAN is an industry standard, in the same sense that a (hardwired) telephone is: All telephones know how to exchange audio and all CAN nodes know how to exchange frames.
But the message sent over CAN are not standardized, just like the use of telephone audio can be done with different languages, different syntaxes, etc.
Zimo sends different messages than MERG¡¯s CBUS protocol, etc.
The other thing about the Z21 is Roco has not published any documentation that describes the protocol on its CAN connection. We don¡¯t even know how to talk to CAN on the Z21 except via the very limited set of messages which are described in the Z21 network protocol documentation.
We do know what protocol the Z21 talks on top of it¡¯s RS485 connection ( this is the XpressNet port(s) ) and the LocoNet connection, but that is because those protocols are published by others. ( RS485, like CAN, is an industry standard used for control systems).
Paul
